Ascites (GI) Flashcards
Define ascites.
A pathological collection of fluid in the peritoneal cavity in the abdomen
What is the most common cause of ascites?
Cirrhosis - approximately 75% of cases
What quantitative measure can indicate the cause of ascites and how can we calculate this?
Serum ascites albumin gradient OR serum to ascitic fluid albumin gradient (SAAG)
[Serum albumin] - [Ascites albumin]
How can SAAG be classified in ascites?
[Serum albumin] - [Ascites albumin]
Serum ascites albumin gradient
- SAAG>11g/L: transudative ascitic fluid (low ascitic protein, hypoalbuminaemia) = portal hypertension
- SAAG<11g/L: exudative ascitic fluid (high ascitic protein) = peritoneal cause
What are some causes of transudative ascites (SAAG>11g/L)? (6)
- portal hypertension - abnormally high pressure within hepatic portal vein
- cirrhosis
- congestive HF
- alcohol-related liver disease (ALD)
- liver failure
- Budd-Chiari syndrome (hepatic vein thrombosis)
What signs are seen in portal hypertension (cause of transudative ascites)? (3)
- caput medusae
- splenomegaly
- ascites
How do we treat oesophageal varices if present in ascites/portal hypertension?
-
terlipressin + IV Abx before endoscopy
1. to stop endoscopic bleeding - variceal band ligation
2. if uncontrolled haemorrhage, must use sengstaken-blakemore tube
3. possibly TIPS (transjugular intrahepatic portosystemic shunt) if refractory - prophylaxis: beta blockers
What are the causes of exudative ascites (SAAG<11g/L)? (4)
- hypoalbuminaemia (nephrotic syndrome, severe malnutrition e.g. Kwashikor)
- intra-abdominal malignancy with peritoneal spread
- infections e.g. TB
- pancreatitis
What are the clinical features of ascites? (5)
- abdominal distension
- early satiety
- weight gain
- dyspnoea
- hepatic encephalopathy - change in handwriting, altered sleep pattern, confusion–>coma
What would you see on examination in ascites? (3 + 3)
- distended abdomen
- shifting dullness (change from dull to resonant when patient changes from supine to lateral decubitus position)
- signs of underlying disease:
- chronic liver disease/cirrhosis - jaundice, spider naevi, palmar erythema, muscle wasting, leukonychia, hepatomegaly/splenomegaly
- heart failure - elevated JVP
- upper abdominal malignancy - Virchow’s node and weight loss
What are some risk factors for ascites? (3)
- potential precipitating factors e.g. dehydration/AKI, hypokalaemia, GI bleed, sepsis
- cirrhosis risk factors e.g. hepatitis
- Fx - haemochromatosis
What is the first-line investigation for new-onset ascites?
Abdominal ultrasound
What investigations are done for ascites? (4)
- abdominal US
- ascitic fluid analysis (underlying cause)
- diagnostic paracentesis (rule out spontaneous bacterial peritonitis which shows polymorphonuclear leukocyte count >250/mm2)
- haematocrit (rule out haematoperitoneum)
What are some common vs uncommon differential diagnoses for ascites?
- common: hepatitis C, ALD, congestive HF, nephrotic syndrome, pancreatitis
- uncommon: hepatitis B, primary biliary cholangitis, autoimmune hepatitis, haemochromatosis, Wilson’s disease, constrictive pericarditis, Budd-Chiari syndrome, chronic renal failure, protein-losing enteropathy
Describe the general management plan for ascites. (5)
- diuretics: spironolactone (aldosterone antagonist) +/- furosemide
- reduce dietary sodium
- therapeutic paracentesis (drainage in tense ascites) - give IV albumin when large volume paracentesis
- fluid restriction in hyponatraemia <125
- monitor weight daily
How do we manage spontaneous bacterial peritonitis in ascites? (4)
- surgical emergency
- IV albumin (prevent hepatorenal syndrome)
- IV Abx - ceftriaxone
- Abx prophylaxis with ciprofloxacin
How do we manage refractory ascites? (2)
- large-volume paracentesis + IV albumin replacement
- transjugular intrahepatic portosystemic shunt (TIPS)
How do we manage hepatic encephalopathy in ascites? (2)
Lactulose (reduces serum ammonia) and rifaximin (can prevent aspiration pneumonia)
How do we manage hepatorenal syndrome in ascites? (3)
- IV albumin
- vasoconstrictor e.g. terlipressin (or midodrine+somatostatin or noradrenaline)
- urgent liver transplant
What are some side effects of spironolactone (diuretic in ascites)? (2)
- hyperkalaemia
- gynaecomastia
What are some complications of ascites?
- abdominal hernias (especially umbilical)
- spontaneous bacterial peritonitis - ascitic fluid infection = abdominal tenderness, fever, altered mental status
- hepatic encephalopathy (hepatic insufficiency = buildup of ammonia in blood –> confusion/comatose, asterixis)
